Suction tube



FIG. 1 is a front elevation view of a suction tube of the present invention;

FIG. 2 is a is a rear elevation view thereof;

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a bottom plan view thereof.

The broken line showing of environmental structure is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a suction tube, as shown and described. 